Pulmonary embolism (PE) is a blockage of the pulmonary artery, the main artery of the lung, or one of its branches by a substance that has travelled from elsewhere in the body (embolism) through the vascular system. Usually, a portion of a deep vein thrombosis (blood clot) breaks free and travels through the vein to the lungs, causing severe breathing difficulty or death.
The causes of pulmonary embolism are:
- Prolonged immobility of the legs
- Excessive dehydration
- Genetic predisposition causing abnormal blood clotting and thrombosis
The symptoms of pulmonary embolism are:
- Painful, swollen legs
- Sudden onset of chest pain
- Shortness of breath
- Rapid pulse
- Coughing up blood
Treatment & Prevention
To prevent a pulmonary embolism, you need to prevent a thrombosis (blood clot). A thrombosis in varicose or superficial veins is normally treated with anti-inflammatory drugs, together with elevating the legs to reduce pressure. Deep vein thrombosis is immediately treated with anticoagulants (blood thinners), together with bed rest and elevation of the legs above heart level to reduce pressure and promote the flow of blood back to the heart. If blood thinners are used for long-term treatment, patients are cautioned not to take certain other medications, especially aspirin, which may interact with them.
When a patient resumes walking, elastic compression of the lower leg controls swelling, collapses the superficial veins and increases blood flow in the deep veins to promote healing. If there is an associated venous ulcer of the ankle, this same treatment promotes healing.
People who are vulnerable to blood clots should not smoke, because tobacco promotes clot formation.
Vascular Disease Foundation
National Heart, Lung and Blood institute